Promax OD-514B Instruction Manual page 29

3. Function of SLOPE switch [22]
The SLOPE [22] switch selects the slope (polarity) triggering signal. Always select
the steepest and the most stable slope or edge. If you are ever in doubt, or have an
unsatisfactory display, try both slopes to find the best way.
+ The sweep is developed from the trigger source waveform as it crosses the
threshold level in a positive-going direction.
- The sweep trigger is developed from the trigger source waveform as it crosses the
threshold level in negative-going direction.
4. Function of TRIG LEVEL control [30] (LOCK [29])
The function of this control is to adjust the triggering level and display a stationary
image. At the instant, the triggering signal has crossed the triggering level set by the
control, the sweep is triggered and a waveform is displayed on the screen. The trigger level
changes in the positive direction (upward) as this control knob is turned clockwise, and it
changes in the negative direction (downward) as the knob is turned counter clockwise. The
characteristic changes are as shown in the following figure. Try to trigger at the mid point of
slow-rise waveforms (as sine and triangular waveforms) since these are usually cleanest
spots on such waveforms. See the following figure:
Page 26
OD-514B, OD-515B & OD-545B INSTRUCTION MANUAL
November 2000